25640128251 has 12 divisors (see below), whose sum is σ = 37079170128. Its totient is φ = 17073374544.

The previous prime is 25640128247. The next prime is 25640128271. The reversal of 25640128251 is 15282104652.

25640128251 is a `hidden beast` number, since 2 + 5 + 640 + 1 + 2 + 8 + 2 + 5 + 1 = 666.

It is not a de Polignac number, because 25640128251 - 2² = 25640128247 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25640128211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1662255 + ... + 1677608.

It is an arithmetic number, because the mean of its divisors is an integer number (3089930844).

Almost surely, 2^25640128251 is an apocalyptic number.

25640128251 is a deficient number, since it is larger than the sum of its proper divisors (11439041877).

25640128251 is a wasteful number, since it uses less digits than its factorization.

25640128251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3340722 (or 3340719 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 36.

The spelling of 25640128251 in words is "twenty-five billion, six hundred forty million, one hundred twenty-eight thousand, two hundred fifty-one".